Running water is an element of life that is taken for granted by persons who are fortunate enough to reside within the developed countries of the world. Most buildings include a system for delivering water from a water main to various points within the building having water outlets, from which the water can be drawn for use.
Most residential and smaller buildings have a one-way water circulation system, wherein water is brought into the building from a nearby water main, and then directed by pipes to the various water outlets. For example, it is common within a single family residential dwelling for a water pipe to extend between the dwelling and the main, and bring water into the interior of the dwelling. Once inside the dwelling, the water is divided between the cold water circulation and the hot water circulation systems. Water that is directed into the hot water circulation system is typically directed to a water heater wherein the water is heated. A pipe emerges from the water heater that then directs the water to the various outlets. To accomplish this, the hot water pipe may have several branches to serve all of the various water outlets.
In a residential type system of the one described above, water that is directed to a particular outlet is not returned to the water heater. Rather, the hot water circulation system has its terminus at one or more of the water outlets. The number of termini that any circulation system has depends upon the number of branches of the circulation system that exits, that, is largely determined by the number of outlets within the dwelling, and the location of the outlets within the dwelling.
One difficulty with such a one-way circulation system, especially when applied to hot water systems, is that over time, hot water that is fed into the water circulation branches will tend to cool. For example, if no one draws any water from a faucet during the night, the first person who wakes up in the dwelling in the morning, and attempts to take a shower will be met with cold water flowing out of the shower head. Such cooling is to be expected, as the ambient temperature surrounding the pipes is generally much less than the typical temperature (e.g. 120 degrees) to which the water heater heats the water.
In order to obtain hot water, the user must run water from the faucet to purge the water that has been resident in the hot water pipes overnight. The water must be run until this pipe-resident water has been purged from the pipe, and replaced with newly delivered water that is concurrently being drawn from the hot water heater. In most residential dwellings, the wait for hot water presents only a minor inconvenience, as the size of most dwellings, and the concomitant volume of water within the pipes is small enough so that only a relatively small amount of water is wasted, and the wait is relatively short.
Although a single circulation system works well for most smaller buildings, certain situations exist wherein a one-way circulation system is highly undesirable. One such situation involves larger buildings wherein the distance between the hot water heater and the outlets is large, and the volume of water in the circulation pipes is great. This is the situation as one would encounter in a large office building. This undesirable situation is exacerbated in large buildings with multiple water outlets, such as hotels and motels.
To overcome the limitations of a one-way circulation system in buildings such as hotels, a loop type re-circulation system is employed wherein water from the water heater is delivered to a hot water outflow pipe, that then delivers the water to the various outlets within a hotel. A return pipe is also provided for returning unused hot water back to the water heater, wherein the water can be reheated and redelivered to the hot water outflow pipe. Through this vehicle, water is circulated constantly within the hot water system, so that, at least in theory, hot water is present at all locations at all times within the re-circulating loop hot water system.
As will be described in more detail in the Detailed Description portion of the application, a re-circulation loop hot water system typically includes several “branches”. These branches are often referred to as risers, as they usually extend vertically at a particular point in the building, which point usually coincides with the water outlets for the rooms on different floors.
One difficulty with serving such a multi-branched re-circulation loop is that all of the branches may not be served evenly. For example, those branches that are furthest away from the heater are less likely to receive their fair share of hot water than those branches that are located closer to the hot water heater. To help equalize the flow among branches, flow limiter valves are often inserted in each branch, that limit the amount of water that can flow out of a particular branch. These flow limiters are typically placed at the downstream end of each branch, so that the water entering the branch is not limited, but that the water leaving the branch is. These flow limiters are typically designed to permit water to flow out of the branch at a pre-determined volumemetric rate, such as 1 to 5 gallons per minute. Although currently existing flow limiter valves are capable of performing their designated tasks in a workman-like manner, room for improvement exists.
In particular, room for improvement exists in reducing the complexity of currently existing flow control valves containing flow limiters. Current practice is to employ a flow control valve in connection with a flow limiter valve and check valve, wherein the three components are in separate housings that must be joined together.
One object of the present invention is to provide a valve for use in a re-circulation system that incorporates a flow control valve, one-way valve, and flow limiter valve within a unitary housing.